Week 1 Understanding Different Battery Chemistry

(1) AIM- Materials & Chemical Reactions Of Different Type Of Lithium-Ion Cells.

SOLUTION- A cell is the unit of a battery, comprised of 4 key components including cathode, anode, electrolyte, and separator. The characteristics of a battery cell play a pivotal role in the overall performance of the Battery. And characteristics of the cell is depending on the materials used for making anode, cathode.

Lithium-ion batteries are secondary batteries. It means that it is a rechargeable battery. So to meet the larger possible performance of the battery, it includes more and more safety, longer life, more power, the larger capacity of storage, e.t.c, different types of materials were used to construct a cell.

So, the below table shows the material used in the cathode and anode of different lithium-ion cells. Also, chemical reactions at cathode and anode are mentioned below table:-

Types	Cathode Material	Anode Materials	Chemical Reaction at Cathode	Chemical Reaction at Anode
LCO	Lithium Cobalt Oxide	Graphite	`Li_(1-x) + CoO_2 + xLi^+ + xe^- implies LiCoO_2`	`Li^+C_6 implies xLi^+ +C_6 +xe^-`
LMO	Lithium Manganese Oxide	Graphite	`Li_(1-x) + Mn_2O_4 + xLi^+ + xe^- implies LiMn_2O_4`	`Li^+C_6 implies xLi^+ +C_6 +xe^-`
NCA	Lithium Nickel Cobalt Aluminium Oxide	Graphite	`Li_(1-x)NiCoAlO_2 + xLi^+ + xe^- implies LiNiCoAlO_2`	`Li^+C_6 implies xLi^+ +C_6 +xe^-`
NMC	Lithium Nickel Manganese Cobalt Oxide	Graphite	`Li_(1-x) + MO_2 + xLi + xe^- implies LiMO_2`	`Li^+C_6 implies xLi^+ +C_6 +xe^-`
LFP	Lithium Iron Phosphate	Graphite	`LiFe_3PO_4 + xLi^+ + xe^+ implies LiFe_2PO_4`	`Li^+C_6 implies xLi^+ +C_6 +xe^-`
LTO	Manganese Oxide	Lithium Titanium Oxide	`4Mn_2O_4 + 4Li^+ + 4e^- implies 4LiMn_2O_4`	`Li_4Ti_5O_12 implies Ti_5O_12 + 4Li^+ + 4e^-`

(2) AIM- Compare The Differences Between Each Type Of Li+ion Batteries Based On Their Characteristics

SOLUTION- Lithium-ion batteries are based on their chemical compositions and they are:-

(I) Lithium Cobalt Oxide (LCO):-

1. It is mostly used in handheld electronics like cell phones, laptops, cameras e.t.c
2. Its nominal voltage is 3.6V.
3. Energy density is also good i.e 150-200 Wh/kg.
4. The life cycle is not soo good i.e 500-1000.
5. Both charge rate (0.7C-1C) and discharge rate(1C) are not soo good.
6. It is risky, especially when gets damaged.
7. Cobalt is scarce and the price is also quite higher.

(II) Lithium Manganese Oxide (LMO):-

1. Used in power tools, medical devices, electric powertrains.
2. Its nominal voltage is 3.7-3.8V.
3. Energy density is not good i.e 100-150 Wh/kg.
4. The life cycle is poor i.e 300-700.
5. Both charge rate (0.7C-1C) and discharge rate(1C) are not soo good.
6. Safer the LCO.
7. High power but less capacity.
8. Price is nearly similar to LCO.

(III) Lithium Nickel Coblat Aluminium (NCA):-

1. Used in medical tools, electric powertrain (tesla)
2. Its nominal voltage is 3.6V.
3. Energy density is higher i.e 200-260 Wh/kg.
4. The life cycle is 500.
5. Both charge rate (0.7C) and discharge rate(1C).

(IV) Lithium Nickel Manganese Cobalt Oxide (NMC):-

1. Used in E-bikes.
2. Its nominal voltage is 3.6 V.
3. Energy density is quite good i.e 150-220 Wh/kg.
4. The life cycle is higher than all other cells discussed above 1000-2000.
5. Both charge rate (0.7C-1C) and discharge rate(1C) are not soo good.
6. Provides high capacity and high power.

(V) Lithium Iron Phosphate (LFP):-

1. Used in portable and stationary which needs a high load currents endurance.
2. Its nominal voltage is lower than all (3.2V).
3. Energy density is lower i.e 90-120 Wh/kg.
4. The life cycle is also higher than NMC (2000-4000).
5. The charge rate and discharge rate are also good (1C).
6. It has a very flat voltage discharge curve but low capacity.
7. One of the safest Li-ions.

(VI) Lithium Titanium Oxide (LTO):-

1. Used in UPS, solar street lighting.
2. Its nominal voltage is very low 2.4 V.
3. Energy density is lowest i.e 65 Wh/kg.
4. The life cycle is also higher than all(3000-7000).
5. Both charge rate is also good (1C) and discharge rate(10C) higher than all.
6. It is expensive.